What happened

On 14 January 2021, the pilot of a Piper PA-30 aircraft planned to conduct circuits for the purpose of running the engines after a prolonged storage period. The pilot’s usual procedure had been to fill the aircraft tanks (to full) prior to flight. On this occasion, instead of filling the tanks, the pilot visually checked the quantity of fuel in the wing tanks and assessed it was sufficient for the planned flight.

A graphic engine monitor unit was installed in the aircraft but was reported to have reverted to factory settings following a flat battery. The pilot therefore deemed this an unreliable source of fuel quantity information.

Shortly after take-off on the fourth circuit, the left engine stopped due to fuel exhaustion. The pilot initiated a turn back to the runway. Once confident of making the runway, the pilot configured the aircraft for landing.

With limited manoeuvrability due to one engine inoperative, and the possibility of the right engine stopping at any moment, the pilot elected to land with a tailwind. This resulted in a higher ground speed on touchdown. The ground speed, combined with the wet grass surface, meant that the braking performance was insufficient to stop the aircraft on the runway remaining. The aircraft overran the runway into a wire fence resulting in minor damage to the nose and wings.

Safety action

As a result of this occurrence, the owner has advised the ATSB that they have made a calibrated dipstick to accurately measure the quantity of fuel in the wing tanks.

Safety message

This incident is a reminder to pilots to ensure sufficient fuel is carried for the proposed flight. The Civil Aviation Safety Authority advisory publication,

Case studies for pilots to learn about fuel management related accidents are documented in the ATSB publication Avoidable Accidents No. 5 – Starved and exhausted: Fuel management aviation accidents.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 29 January 2021, at 0655 Coordinated Universal Time, a multi-purpose vessel encountered heavy seas in the Southern Ocean. The 6-metre swell and confused sea state ^[1] caused the vessel to roll heavily, listing more than 30 degrees. As a result of this movement, several bundled wire restraints on battery racks failed and numerous batteries fell to the floor of the top deck battery room (Figure 1).  

Wires to the batteries were cut and at least two of the batteries short circuited internally between the cells. This resulted in a fire, which triggered an alarm on the bridge. The captain initiated the emergency response procedures and the fire was extinguished.

Figure 1: Battery room after the fire was extinguished

Source: Vessel operator

Battery racks

The battery room contained multiple shelved racks with large batteries secured to them. These racks used an L-shaped frame to prevent fore and aft movement, and metal brackets or bundled wires to prevent any lateral movement in the rack. The batteries that fell from the racks, including the two that had confirmed fire damage, were secured by bundled wire straps. These had been 

installed 5 months prior to the occurrence. The other batteries were secured to the racks by heavy metal brackets that bolted into the rack frame. Figure 2 depicts a battery secured with both types. The large brackets were the normal method of restraint and it could not be determined why they were not used to secure the more recently delivered batteries or why some batteries were secured by both types of restraints. The bundled wire straps proved to be inadequate in the heavy swell of the Southern Ocean.

Figure 2: Battery rack with both types of restraints  

Safe Work guidance

While there are no mandated standards for battery racks on ships, securing loose items prior to departure is a key principle of good seamanship. The Seacare Authority Code of Practice Approval 2018 - Health and Safety in Shipboard Work, including Offshore Support Vessels (paragraph 12.5) stated 'Batteries should be kept battened into position to prevent shifting in rough weather’. In this occurrence, the batteries were secured, although inadequately so for the prevailing conditions. The departure checklist used by the operator included securing loose items above deck in preparation for heavy weather and was completed by the crew.

Safety action

The operator of the vessel advised the ATSB they have taken the following safety actions:

• all battery rooms were checked for suitable sea fastening
• the bundled wire securing bands were immediately replaced with the original metal securing brackets or another equally robust arrangement
• damaged batteries were replaced as required
• a meeting with involved parties was held to discuss the lessons learned and corrective action.

Safety message

Although believed to be sufficient at the time of installation, the methods used to secure the batteries were inadequate for the conditions experienced in the Southern Ocean. At sea, particularly in heavy weather, unsecured items risk being damaged and may also pose a danger to the crew, or, as in this case, the safety of the ship. The risk to life associated with an emergency such as a major shipboard fire, is significantly increased when it occurs in heavy weather, far out to sea, where any possibility of assistance from ashore or from another ship is significantly reduced.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Confused sea state: A highly disturbed water surface without a single, well-defined direction of wave travel.

What happened

On 29 January 2021, the pilot of a Britten-Norman BN-2A-21 Islander prepared to conduct a charter flight from Horn Island to Saibai Island, Queensland, with three passengers. The pilot obtained a weather forecast for the planned route, which included the probability of isolated embedded thunderstorms, and weather reports from two pilots operating in the area. The pilot assessed that the conditions were suitable for the flight to be conducted and planned to operate under instrument flight rules.^[1]

About 20 minutes after departing Horn Island, while maintaining 7,000 ft and in instrument meteorological conditions,^[2] the aircraft entered an embedded thunderstorm cell and encountered moderate turbulence. The pilot slowed the aircraft to turbulence penetration speed and executed a 180° turn to exit the cell.

Once clear of turbulence, the pilot checked on the passengers’ welfare as they were visibly affected by the experience. There were no injuries. The pilot descended the aircraft until clear of cloud. The pilot then commenced a diversion to Yam Island, before electing to return the aircraft to Horn Island (Figure 1).

Figure 1: Aircraft flight path  

Source: FlightAware, annotated by the ATSB

Safety message

The primary protection against thunderstorm-related turbulence is avoidance. In the wet season in the tropics, thunderstorm cells should be avoided by large margins. The ATSB (2005) report, General Aviation Pilot Behaviours in the Face of Adverse Weather, identified that ‘weather-related general aviation accidents remain one of the most significant causes for concern in aviation safety’. Addressing this requires pilots to continuously evolve their decision making.

Thorough pre-flight planning, in-flight weather reports, local knowledge and reports from other pilots operating in the area can assist to build a picture of what is happening in the environment. Even with good preparation, as in this incident, an embedded thunderstorm cell may be difficult to see and avoid without on-board weather radar.

ATSB investigations AO-2017-102 and AO-2019-069 provide examples where flight into or near thunderstorms have resulted in damage to aircraft and the loss of life.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Instrument flight rules (IFR): a set of regulations that permit the pilot to operate an aircraft to operate in instrument meteorological conditions (IMC), which have much lower weather minimums than visual flight rules (VFR). Procedures and training are significantly more complex as a pilot must demonstrate competency in IMC conditions while controlling the aircraft solely by reference to instruments. IFR-capable aircraft have greater equipment and maintenance requirements.
2. Instrument meteorological conditions (IMC): weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules (IFR), rather than by outside visual reference. Typically, this means flying in cloud or limited visibility. 

What happened

On 28 January 2021, a student pilot was conducting a solo local training flight in a Cessna 152. The aircraft departed Bacchus Marsh, Victoria, with 35 L of fuel on board. As the aircraft was going into maintenance the next day, the student was advised by their instructor to return from the flight with minimum fuel remaining. The flight school’s policy stated that the required minimum remaining fuel was 19 L as a fixed reserve, and an additional 5 L fuel was to be allocated for taxiing. For the useable fuel on board, the policy and fuel planning figures would have allowed for 26 minutes of flight. The total recorded engine-run time for the taxi and flight was 1.2 hours.

The aircraft landed at Bacchus Marsh with 15 L of fuel remaining, which was confirmed when maintainers drained the tank the next day. 

Safety action

The flight school’s fuel policy is under review and a plan to further educate staff and students is being developed.

Safety message

This incident highlights the importance of clear communication between instructors and students. Instead of giving the student a timeframe, the instructor gave a fuel-remaining measurement, which is harder to gauge accurately, and led to the student using fixed reserve fuel. Additionally, other options should be explored to bring the aircraft to minimum fuel for maintenance instead of using a student on a solo training flight.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 15 December 2020, at about 1900 Eastern Daylight-saving Time,[1] the crew of a Leonardo AW139 helicopter were conducting the winch retrieval of three people stranded on a cliff near Childers Cove, Victoria. The crew comprised the pilot, aircrew officer and a paramedic.

The paramedic was winched to the ground and recovered the first stranded person. The aircrew officer then manoeuvred the paramedic and the first person into the aircraft cabin. To allow them to move into the aircraft seats, the aircrew officer winched out some cable to provide slack in the cable. During this winch-out procedure, the slack cable was dispensed onto the aircraft floor and out the cabin door. The aircrew officer was aware that the cable was outside the cabin, but not the length of cable that was outside the cabin, and the looped section was not visible. When the aircrew officer commenced the winch-in of the hook assembly, the cable failed (Figure 1).

The aircrew officer secured the loose end of the winch cable and the pilot landed the helicopter in a nearby carpark to assess the situation. It was found that the cable had looped around the right undercarriage shock absorber trunnion resulting in the failure of the winch cable and damage to several undercarriage components.

Figure 1: Reconstruction of cable fouling and severed winch cable hook assembly

Source: Operator

The helicopter was inspected on site shortly before last light by one of the operator’s engineers and was cleared to return to base. However, it was later determined that the damage to the undercarriage rendered the helicopter unserviceable.

Safety action

As a result of this occurrence, the operator has advised the ATSB that they have taken the following safety actions:

• A Safety Alert has been promulgated throughout the company to reinforce the importance of cable control during all phases of winching operations.
• All personnel have been reminded of the general safety philosophy of the company, which demands that safety related activities, including aircraft inspections and checks, are not rushed nor influenced by time pressures. Any activity should be stopped immediately if any person has any doubt about the safety in relation to a particular operation they are involved in.
• A learning package is being developed to facilitate sharing of the incident details and findings within the company and other helicopter emergency medical service operators.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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[1]     Eastern Daylight-savings Time (ESuT): Coordinated Universal Time (UTC) + 11 hours.

What happened

On 25 December 2020, a Raytheon (Beechcraft) A36 aircraft was departing from a private airstrip on a property near Pingrup, Western Australia, for a private flight to Jandakot, Western Australia, with the pilot and four passengers on board.

During the take-off to the east, when about halfway down the runway, the pilot detected a sudden and severe wind change. The northerly wind became gusty and variable, which affected the aircraft’s airspeed, resulting in a stall warning. When the stall warning sounded, the aircraft was approximately 10 ft above the runway, but the pilot was having difficulty maintaining altitude.

The pilot elected to reject the take-off and land but was unable to stop the aircraft before the end of the runway. The aircraft overran the runway and struck a fence, resulting in substantial damage to the propeller, wings, landing gear and fuselage. There were no injuries to the pilot or passengers.

Safety action

As a result of this accident, the pilot has advised the ATSB that they are planning to install a second windsock at the eastern end of the airstrip, and construct an additional flight strip running in a north/south direction.

Safety message

This accident highlights the importance of early decision making for pilots, specifically when rejecting a take-off. Instead of attempting to keep the aircraft in the air operating below safe flying speed, the pilot made the safer decision to land back on the runway. Although the aircraft was damaged, the pilot and the passengers were uninjured.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 23 December 2020, the pilot of a Robinson R22 helicopter was preparing to take off from a private property near Derby, Western Australia. The helicopter landing site was covered with rubber matting made from conveyor belts as a means of limiting dust when landing (Figure 1).

As the helicopter became airborne, it moved backwards slightly due to a headwind, resulting in the heel of the skid sliding between two overlapping sheets of matting (Figure 2). As the pilot attempted to gain height, the skid did not free itself and the helicopter pitched back and rolled to the left. The pilot recognised the early onset of dynamic rollover and attempted to recover by lowering the collective.^[1]While that action prevented a rollover, it resulted in a hard landing and substantial damage to the helicopter.

Figure 1: Landing site conveyor belt matting

Figure 2: Snag hazard

Source: Aircraft operator

Helicopter static and dynamic rollovers

ATSB occurrence brief AB-2020-015 included the following explanation for helicopter rollovers.  

Static rollover occurs when a helicopter is pivoted about one of its landing skids or wheels and the helicopter’s centre of gravity passes outside the in-contact skid or wheel. Once in this position, removal of the original force that raised the helicopter to that angle will not stop the helicopter from rolling further. This angle is termed the ‘static rollover angle.’

A rotors-running helicopter resting with one landing skid or wheel on the ground may, without appropriate pilot input, commence rolling. Under certain circumstances, this roll cannot be controlled, and the helicopter rolls over. This condition is known as ‘dynamic rollover’ and is a function of the interaction between the:

- horizontal component of the total rotor thrust (or lift) acting about the point of ground contact 
- weight of the aircraft, initially acting between the helicopter’s skid landing gear or wheels. This second, counter-rolling moment decreases the greater the roll.

Recovery from dynamic rollover is by smoothly lowering the collective lever while controlling any tendency to roll in the opposite direction with cyclic to re-establish the helicopter’s weight evenly on the ground. In general, the application of smooth collective inputs is more effective in avoiding rollover issues than using the cyclic control.

Safety action

As a result of this incident, the operator advised the ATSB they have taken the following safety action:

• removed rubber conveyor belt matting from all company helicopter landing sites 
• issued an internal safety alert to all pilots regarding the incident, reminding them of the requirements to ensure company helicopter landing sites are clear of any objects that could cause dynamic rollover on take-off
• reminded pilots how dynamic rollover can occur and the appropriate recovery technique.

Safety message

This was an unfortunate outcome for an operator who in addressing one problem, the potential for ‘brownout’^[2]when landing, inadvertently created another hazard that resulted in damage to the helicopter. ATSB occurrence brief AB-2020-024 illustrates the potential consequences of ‘brownout’ when operating in dry and dusty conditions.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Collective: a primary helicopter flight control that simultaneously affects the pitch of all blades of a lifting rotor. Collective input is the main control for vertical velocity.
2. Brownout condition: is an in-flight visibility restriction due to dust or sand in the air. In a brownout, the pilot cannot see nearby objects which provide the outside visual references necessary to control the aircraft near the ground. This can cause spatial disorientation and loss of situational awareness leading to an accident.

What happened

On the morning of 23 November 2020, a Cessna 150 departed Peterborough, Victoria on a private flight to Deniliquin, New South Wales, with the pilot and one passenger on board. The en-route weather forecast obtained prior to flight indicated a band of marginal weather moving to the east followed by clearing weather behind. The pilot assessed that the conditions on the route chosen would be initially suitable for flight under VFR^[1] with conditions improving during the day.

During the flight, the weather began to deteriorate approaching the Ballarat area. The pilot observed increasing overcast cloud on the intended track and was forced to descend to stay in VMC.^[2] Approximately 15 NM south of Ballarat airfield, at 800 ft and now several miles right of track, the pilot received the weather from the aerodrome weather information service which was indicating a cloud ceiling at Ballarat of 5,000 ft. After the sudden appearance of wind turbines off to the right of track, the instrument-rated pilot decided to commence a climb to get above the cloud, which was believed to be 1,000 ft thick. Passing 3,500 ft the airspeed indicator became unreliable and was fluctuating significantly despite the pitot heat being on. The decision to reverse course and descend out of cloud was made. The pilot became visual with the ground about 200 ft above the trees and began searching for a suitable landing area.

As the pilot searched, it became increasingly difficult to maintain visual reference with the ground and they decided to immediately land in a paddock. Selecting a paddock, the pilot lined up on approach and on short final a wire fence was sighted which required an adjustment just prior to touchdown. This adjustment increased the ground roll and the aircraft passed through another fence before the wing tip collided with a small shed and the aircraft came to rest on an embankment.

Figure 1: Aircraft in situ post collision

Source: Operator

• Pilot comments – In hindsight the pilot suggested they could have either delayed the departure of the flight until the marginal weather had passed or planned a route further to the west to remain clear of it altogether.

Safety message

The ATSB continues to investigate weather-related general aviation accidents. VFR into IMC remains one of the most significant causes for concern in aviation safety; the often-fatal outcomes of these accidents are usually avoidable. In the 5 years prior to the occurrence, there were 57 reported VFR into IMC occurrences, 7 of which resulted in accidents, with 10 fatalities.

The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns is inflight decision-making.

The decision whether to proceed is the first decision the VFR pilot faces when confronted with less than visual meteorological conditions. Flight Safety Australia article '178 seconds to live' illustrates the stark reality of attempting to fly in IMC conditions without adequate training.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Visual flight rules (VFR): a set of regulations that permit a pilot to operate an aircraft only in weather conditions generally clear enough to allow the pilot to see where the aircraft is going.
2. Visual Meteorological Conditions (VMC): an aviation flight category in which visual flight rules (VFR) flight is permitted – that is, conditions in which pilots have sufficient visibility to fly the aircraft while maintaining visual separation from terrain and other aircraft.

What happened

On the morning of 20 October 2020, a Piper PA-28-181 departed Bankstown Airport on a private flight to Gilgandra, New South Wales, with the pilot as the sole occupant. The en-route weather forecast obtained the morning of departure indicated some cloud over the Blue Mountains to the west of Sydney, but the pilot assessed that conditions would be suitable for flight under visual flight rules (VFR).

After departure, the pilot deviated off the direct track to avoid active restricted airspace before manoeuvring to resume the flight-planned track. The pilot reported that there were scattered clouds in the area at the time. While making the track adjustment, the pilot diverted their attention to the flight log and maps. When the pilot looked up, the aircraft had entered an area of low thick clouds and the pilot initiated a turn to vacate the area.

During the turn, the pilot became disoriented in cloud and the aircraft entered a spiral dive. The pilot recovered control of the aircraft clear of cloud, but the aircraft had descended over 2,000 ft and was surrounded by mountainous terrain. With low cloud over the mountains, visual meteorological conditions^[1] did not exist. To maintain terrain clearance, the pilot initiated a climbing turn, which subsequently took the aircraft back into cloud.

Once at a safe altitude, the pilot attempted to contact air traffic control (ATC) with a request but was twice asked to ‘stand by’. Approximately 2 minutes after the first radio call, the pilot made a PAN PAN^[2] call reporting that the aircraft was ‘VFR in cloud’. The controller immediately responded and provided assistance for the next 16 minutes, guiding the pilot away from high terrain and to an area of clear of cloud. Once below cloud, the pilot resumed visual navigation back to Bankstown.

Safety message

The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns is inflight decision-making.

The decision to proceed is the first decision the VFR pilot faces when confronted with less than visual meteorological conditions. Flight Safety Australia article ‘178 seconds to live’, illustrates the stark reality of attempting to fly in IMC conditions without adequate training.

The ATSB strongly urges pilots to seek assistance from ATC as soon as conditions deteriorate. Controllers are trained to handle such an occurrence and providing them with accurate information on your situational awareness and in-flight conditions will allow them to provide the best possible assistance.

The ATSB continues to investigate weather-related general aviation accidents. VFR into IMC remains one of the most significant causes for concern in aviation safety; the often-fatal outcomes of these accidents are usually avoidable. In the 5 years prior to the occurrence, there were 56 reported VFR into IMC occurrences, 7 of which resulted in accidents, with 10 fatalities.

The ATSB publication Accidents involving Visual Flight Rules pilots in Instrument Meteorological Conditions provides investigation findings, case studies and further reading on managing the risks of flying in reduced visibility.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

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1. Visual Meteorological Conditions (VMC): an aviation flight category in which visual flight rules (VFR) flight is permitted – that is, conditions in which pilots have sufficient visibility to fly the aircraft while maintaining visual separation from terrain and other aircraft.
2. PAN PAN: an internationally recognised radio call announcing an urgency condition which concerns the safety of an aircraft or its occupants but where the flight crew does not require immediate assistance.

What happened

On 31 October 2020, at 0605 Eastern Daylight-saving Time, the pilot of a Kavanagh Balloons B425-581 balloon was preparing for launch near Maitland, New South Wales, with 20 passengers on board. The balloon was to operate in company with another seven passenger-carrying charter balloons and was the second to launch.

The pilot inadvertently released the launch restraint with sufficient heat being applied to the envelope only to become airborne (due to false lift) but not to climb. The balloon then travelled approximately 100 m downwind at 50 ft above the ground before coming into contact with the trees (Figure 1). This resulted in damage to seventeen panels of the balloon envelope. The pilot and passengers were uninjured.

Figure 1: Approximate balloon track

Source: Operator, annotated by ATSB

Safety message

The Australian Ballooning Federation’s Pilot Training Manual Part 5 Aerostatics and Airmanship describes the effects of false lift and the importance of ensuring the flight path is clear of obstacles during launch.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.